Ipv6 Transition Technologies; Dual Stack; Tunneling; Protocols And Standards - HP 5920 Series Configuration Manual

Figure 54 Path MTU discovery process
The source host sends a packet no larger than its MTU to the destination host.
1.
If the MTU of a device's output interface is smaller than the packet, the device discards the packet
2.
and returns an ICMPv6 error packet containing the interface MTU to the source host.
After receiving the ICMPv6 error packet, the source host uses the returned MTU to limit the packet
3.
size, performs fragmentation, and sends the packets to the destination host.
Step 2 and step 3 are repeated until the destination host receives the packet. In this way, the
4.
source host finds the minimum MTU of all links in the path to the destination host.

IPv6 transition technologies

IPv6 transition technologies enable communication between IPv4 and IPv6 networks. Several IPv6
transition technologies can be used in different environments and periods.

Dual stack

Dual stack is the most direct transition approach. A network node that supports both IPv4 and IPv6 is a
dual-stack node. A dual-stack node configured with an IPv4 address and an IPv6 address can forward
both IPv4 and IPv6 packets. An application that supports both IPv4 and IPv6 prefers IPv6 at the network
layer. Dual stack is suitable for communication between IPv4 nodes or between IPv6 nodes. It is the basis
of all transition technologies. However, it does not solve the IPv4 address depletion issue because each
dual stack node must have a globally unique IPv4 address.

Tunneling

Tunneling uses one network protocol to encapsulate the packets of another network protocol and
transfers them over the network. For more information about tunneling, see

Protocols and standards

Protocols and standards related to IPv6 include:
RFC 1881, IPv6 Address Allocation Management
•
RFC 1887, An Architecture for IPv6 Unicast Address Allocation
•
RFC 1981, Path MTU Discovery for IP version 6
•
• RFC 2375, IPv6 Multicast Address Assignments
RFC 2460, Internet Protocol, Version 6 (IPv6) Specification
•
118
"Configuring tunneling."